Generally, a rotary switch mechanism is a mechanism that is rotated in either a clockwise direction or an anti-clockwise direction. For example, the rotary switch mechanism is usually installed on an acoustical device for adjusting sound volume or changing broadcast channels.
With the increasing development of science and technology, the applications of the rotary switch mechanism are gradually expanded. Generally, as shown in FIG. 1, the rotary switch mechanism 10 is installed on a keyboard device 1 of a computer system in order to enhance the function of the keyboard device 1. By operating the rotary switch mechanism 10, a sound volume adjustment command of a video player program, a text file proportional scale command or an image file proportional scale command in the computer system may be executed.
Hereinafter, the internal structures and the operating principles of a conventional rotary switch mechanism will be illustrated with reference to FIGS. 2 and 3. FIG. 2 is a schematic exploded view illustrating a conventional rotary switch mechanism. FIG. 3 is a schematic perspective view illustrating the outward appearance of the conventional rotary switch mechanism. As shown in FIGS. 2 and 3, the conventional rotary switch mechanism 2 comprises a circuit board 20, a rotatable member 21, a push button 22, a rotary switch 23, an elastic element 24, a first push switch 25, a second push switch 26, a third push switch 27, a fourth push switch 28 and a fifth push switch 29.
The circuit board 20 has a mounting aperture 201. The rotatable member 21 has plural projecting parts 211, which are arranged at the periphery of the rotatable member 21. The push button 22 comprises a central button part 221, a ring-shaped part 222 and a fixing part 223. The ring-shaped part 222 is connected with the central button part 221 and arranged around the central button part 221. The fixing part 223 is disposed on the ring-shaped part 222. After the fixing part 223 is engaged with the mounting aperture 201 of the circuit board 20, the push button 22 is fixed on the circuit board 20. The five push switches 25, 26, 27, 28 and 29, the rotary switch 23 and the elastic element 24 are all disposed on the circuit board 20. In addition, the five push switches 25, 26, 27, 28 and 29 are disposed under the push button 22. The rotary switch 23 is arranged beside the push button 22. In addition, the rotary switch 23 has a handle part 231.
Upon rotation of the rotatable member 21 of the rotary switch mechanism 2, the plural projecting parts 211 of the rotatable member 21 are synchronously rotated. As the projecting parts 211 are rotated, the projecting parts 211 interact with the handle part 231 of the rotary switch 23 so as to swing the handle part 231. As the handle part 231 is swung, a rotation signal is generated. In response to the rotation signal, a specified command (e.g. the sound volume adjustment command) is executed. Moreover, upon rotation of the rotatable member 21, the handle part 231 may be swung in either a clockwise direction or an anti-clockwise direction to generate two different rotation signals. According to the two rotation signals, a sound volume increasing command and a sound volume decreasing command are respectively executed. On the other hand, during the process of rotating the rotatable member 21, the elastic element 24 is contacted with plural notches (not shown) that are arranged at the inner periphery of the bottom side of the rotatable member 21 so as to result in an elastic force. Due to the elastic force, the rotation of the rotatable member 21 results in a multi-step rotating feel to the user.
By pressing the central button part 221 of the conventional rotary switch mechanism 2, the central button part 221 is moved downwardly to push against the first push switch 25 under the central button part 221. As a result, the first push switch 25 is triggered to generate a first triggering signal. In response to the first triggering signal, another specified command (e.g. a clicking and selecting command) is executed. By pressing the ring-shaped part 222 of the conventional rotary switch mechanism 2, the second push switch 26 under the ring-shaped part 222 is triggered to generate a second triggering signal. In response to the second triggering signal, another specified command (e.g. a text file proportional scale-up command) is executed. By pressing the ring-shaped part 222 of the conventional rotary switch mechanism 2, the third push switch 27 is triggered to generate a third triggering signal. In response to the third triggering signal, another specified command (e.g. a text file proportional scale-down command) is executed. Moreover, by triggering the fourth push switch 28 and the fifth push switch 29, different commands (e.g. an image file proportional scale-up command and an image file proportional scale-down command) are executed. The operations of the fourth push switch 28 and the fifth push switch 29 are similar to those of the second push switch 26 and the third push switch 27, and are not redundantly described herein.
From the above discussions, the conventional rotary switch mechanism 2 may be operated to execute at most four commands. That is, the sound volume adjustment command is executed by rotating the rotatable member 21, the clicking and selecting command is executed by pressing the central button part 221, the text file proportional scale command is executed by pressing the ring-shaped part 222, and the image file proportional scale command is executed by pressing the ring-shaped part 222. The conventional rotary switch mechanism 2, however, still has some drawbacks. For example, since the conventional rotary switch mechanism 2 can execute at most four commands, the conventional rotary switch mechanism 2 fails to meet the user's requirements. In addition, since the rotatable member 21 and the push button 22 of the conventional rotary switch mechanism 2 are in contact with each other, upon rotation of the rotatable member 21, the jointing regions between the rotatable member 21 and the push button 22 may rub against each other. Since a long-termed use may abrade the structure of the conventional rotary switch mechanism 2, the use life of the conventional rotary switch mechanism 2 is shortened. Moreover, since the five push switches 25, 26, 27, 28 and 29 of the conventional rotary switch mechanism 2 are disposed under the rotatable member 21, if the force exerted on the rotatable member 21 is unevenly distributed during the process of rotating the rotatable member 21, the rotatable member 21 is readily tilted. Since the ring-shaped part 222 of the push button 22 is also tilted, the possibility of erroneously touching the push switches 25, 26, 27, 28 and 29 will be increased. Under this circumstance, an erroneous operation problem possibly occurs.